This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. CryoEM is capable of resolving density map to 3.5 to 5 Angstrom resolution. A challenge is to build robust and accurate model. We are exploring the use of Rosetta with cryoEM map restraints to optimize initial model which was built by a variety of methods.